///////////////////////////////////////////////////////////////
//  Copyright 2012 John Maddock. Distributed under the Boost
//  Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt

#ifndef BOOST_MATH_MAX_DIGITS10_HPP
#define BOOST_MATH_MAX_DIGITS10_HPP

namespace nil {
    namespace crypto3 {
        namespace multiprecision {
            namespace detail {

                template<unsigned digits>
                struct calc_max_digits10 {
                    static constexpr unsigned max_digits_10(unsigned d) {
                        //
                        // We need ceil(log10(2) * d) + 1 decimal places to
                        // guarantee round tripping, see:
                        // https://www.exploringbinary.com/number-of-digits-required-for-round-trip-conversions/ and
                        // references therein.  Since log10(2) is irrational, then d*log10(2) will never be exactly an
                        // integer so we can replace by trunc(log10(2) * d) + 2 and avoid the call to ceil:
                        //
                        return static_cast<unsigned>(0.301029995663981195213738894724493026768189881462108541310 * d) +
                               2;
                    }
                    static constexpr const unsigned value = max_digits_10(digits);
                };

                template<unsigned digits>
                struct calc_digits10 {
                    static constexpr unsigned digits_10(unsigned d) {
                        //
                        // We need floor(log10(2) * (d-1)), see:
                        // https://www.exploringbinary.com/number-of-digits-required-for-round-trip-conversions/
                        // and references therein.
                        //
                        return static_cast<unsigned>(0.301029995663981195213738894724493026768189881462108541310 *
                                                     (d - 1));
                    }
                    static constexpr const unsigned value = digits_10(digits);
                };

            }    // namespace detail
        }        // namespace multiprecision
    }            // namespace crypto3
}    // namespace nil

#endif
